Introduced the theory of three types of hazardous sources, and it recognized and analysed such three types of hazardous sources as the factor of inherent hazardous source, factor of inducing hazardous source and facto...Introduced the theory of three types of hazardous sources, and it recognized and analysed such three types of hazardous sources as the factor of inherent hazardous source, factor of inducing hazardous source and factor of men, which affect the safety and reliability of coal-dust explosion risk system and then builds up the risk factor indices of coal-dust explosion according to analysis of conditions inducing the coal-dust explosion. It fixes the risk degree of coal-dust explosion risk system by analyzing loss probability and loss scope of risk system and by means of the probabilistic hazard evaluation method and risk matrix method, etc.. According to the feature of strong capability of nonlinear approximation of BP neural network, the paper designed the structure of BP neural network for the risk evaluation of the mine coal-dust explosion with BP neural network. And the weight of the network was finally determined by training the given samples so that the risk degree of samples to be measured could be exactly evaluated and the risk of mine coal-dust explosion could be alarmed in good time.展开更多
The spacing–burden(S/B) ratio plays significant role on rock fragmentation and proper utilization of explosive energy to minimize the undesirable damage.Low S/B ratio generates fine fragments due to pressure rings co...The spacing–burden(S/B) ratio plays significant role on rock fragmentation and proper utilization of explosive energy to minimize the undesirable damage.Low S/B ratio generates fine fragments due to pressure rings coalescence of two blast holes,whereas boulder generations were observed above optimum S/B ratio.Both conditions are not acceptable because of wastage of explosive energy.Therefore,to resolve this issue,a numerical model study was conducted to optimize the S/B ratio and to envisage its effect on rock fragmentation based on utilization of explosive energy.Finite element simulation tool was used to see the extent of two blast hole influence area variation with varying S/B ratio.The better results were obtained at S/B ratio of 1:2 with optimum utilization of peak explosive energy.The performance was observed based on peak kinetic energy,peak pressure,radial and hoop stresses on centre of the two blast holes,where pressure rings coalescence.展开更多
According to hazard theory and the principle of selecting assessment index,combining the causes and mechanisrn of gas explosion, established assessment index system of gas explosion in heading face. Based on the metho...According to hazard theory and the principle of selecting assessment index,combining the causes and mechanisrn of gas explosion, established assessment index system of gas explosion in heading face. Based on the method of gray clustering, principle of BP neural network and characters of gas explosion in heading face, safety assessment procedural diagram of BP neural network on gas explosion hazard in heading face is designed. Meanwhile, concrete heading face of the gas explosion hazard is assessed by safety assessment method of BP neural network and grades of comprehensive safety assessment are got. The static and dynamic safety assessment can be achieved by this method. It is practical to improve safety management and to develop safety assessment technology in coalmine.展开更多
A probabilistic risk assessment procedure is developed which can predict risks of explosive blast damage to built infrastructure, and when combined with life-cycle cost analysis, the procedure can be used to optimise ...A probabilistic risk assessment procedure is developed which can predict risks of explosive blast damage to built infrastructure, and when combined with life-cycle cost analysis, the procedure can be used to optimise blast mitigation strategies. The paper focuses on window glazing since this is a load-capacity system which, when subjected to blast loading, has caused significant damage and injury to building occupants. Structural reliability techniques are used to derive blast reliability curves for annealed and toughened glazing subjected to explosive blast for a variety of threat scenarios. The probabilistic analyses include the uncertainties associated with blast modelling, glazing response and glazing failure criteria. Damage risks are calculated for an individual window and for windows in the facade of a multi-storey commercial building. The paper shows an illustrative example of how this information, when combined with risk-based decision-making criteria, can be used to optimise blast mitigation strategies.展开更多
Recently, the mode approximation method(MAM) has been adopted to analyze beam elements against blast load. However, in real cases, the main structural element of an underground structure is slab and side wall since th...Recently, the mode approximation method(MAM) has been adopted to analyze beam elements against blast load. However, in real cases, the main structural element of an underground structure is slab and side wall since they not only support the structure itself but also may sustain external loads from blast, earthquake, and other kinds of impact. In the present study, the MAM is extended from beam to plate elements and the soil-structure interaction is considered and simplified when calculating structural response under blast load. Pressure-impulse diagrams are generated accordingly for further quick damage assessment.展开更多
文摘Introduced the theory of three types of hazardous sources, and it recognized and analysed such three types of hazardous sources as the factor of inherent hazardous source, factor of inducing hazardous source and factor of men, which affect the safety and reliability of coal-dust explosion risk system and then builds up the risk factor indices of coal-dust explosion according to analysis of conditions inducing the coal-dust explosion. It fixes the risk degree of coal-dust explosion risk system by analyzing loss probability and loss scope of risk system and by means of the probabilistic hazard evaluation method and risk matrix method, etc.. According to the feature of strong capability of nonlinear approximation of BP neural network, the paper designed the structure of BP neural network for the risk evaluation of the mine coal-dust explosion with BP neural network. And the weight of the network was finally determined by training the given samples so that the risk degree of samples to be measured could be exactly evaluated and the risk of mine coal-dust explosion could be alarmed in good time.
文摘The spacing–burden(S/B) ratio plays significant role on rock fragmentation and proper utilization of explosive energy to minimize the undesirable damage.Low S/B ratio generates fine fragments due to pressure rings coalescence of two blast holes,whereas boulder generations were observed above optimum S/B ratio.Both conditions are not acceptable because of wastage of explosive energy.Therefore,to resolve this issue,a numerical model study was conducted to optimize the S/B ratio and to envisage its effect on rock fragmentation based on utilization of explosive energy.Finite element simulation tool was used to see the extent of two blast hole influence area variation with varying S/B ratio.The better results were obtained at S/B ratio of 1:2 with optimum utilization of peak explosive energy.The performance was observed based on peak kinetic energy,peak pressure,radial and hoop stresses on centre of the two blast holes,where pressure rings coalescence.
基金Supported by Natural Science Fundation of Shaanxi(2001C38), Education Committee Science Fundation of Shaanxi(00J214) and Post-Doctoral Science Fundation of China(2003034462)
文摘According to hazard theory and the principle of selecting assessment index,combining the causes and mechanisrn of gas explosion, established assessment index system of gas explosion in heading face. Based on the method of gray clustering, principle of BP neural network and characters of gas explosion in heading face, safety assessment procedural diagram of BP neural network on gas explosion hazard in heading face is designed. Meanwhile, concrete heading face of the gas explosion hazard is assessed by safety assessment method of BP neural network and grades of comprehensive safety assessment are got. The static and dynamic safety assessment can be achieved by this method. It is practical to improve safety management and to develop safety assessment technology in coalmine.
文摘A probabilistic risk assessment procedure is developed which can predict risks of explosive blast damage to built infrastructure, and when combined with life-cycle cost analysis, the procedure can be used to optimise blast mitigation strategies. The paper focuses on window glazing since this is a load-capacity system which, when subjected to blast loading, has caused significant damage and injury to building occupants. Structural reliability techniques are used to derive blast reliability curves for annealed and toughened glazing subjected to explosive blast for a variety of threat scenarios. The probabilistic analyses include the uncertainties associated with blast modelling, glazing response and glazing failure criteria. Damage risks are calculated for an individual window and for windows in the facade of a multi-storey commercial building. The paper shows an illustrative example of how this information, when combined with risk-based decision-making criteria, can be used to optimise blast mitigation strategies.
基金Supported by the National Natural Science Foundation of China(No.51308388)the Natural Science Foundation of Tianjin(No.13JCQNJC07500)the State Key Laboratory of Hydraulic Engineering Simulation and Safety,Tianjin University
文摘Recently, the mode approximation method(MAM) has been adopted to analyze beam elements against blast load. However, in real cases, the main structural element of an underground structure is slab and side wall since they not only support the structure itself but also may sustain external loads from blast, earthquake, and other kinds of impact. In the present study, the MAM is extended from beam to plate elements and the soil-structure interaction is considered and simplified when calculating structural response under blast load. Pressure-impulse diagrams are generated accordingly for further quick damage assessment.
